941 with moisture in engine help please

2 weeks ago i started it up for the first time in around 8 months, and after few mins it started overheating so shut it down and had to add about 3 gallons of antifreeze.
used it for couple of hours after that and all seemed fine and antifreeze was still full and oil level still perfect.

now for the past few days ive been clearing a spot for a hay barn, yesterday when shut it off all seemed fine.

went to start it today and the engine ran away when i cranked it, turning the fuel lever off did nothing, so i pulled the air intake and smothered it off with my shirt. and noticed the air filter cap had come loose, that lead to me cleaning the filter out, which lead to me having to take the breather cap off the top of the valve cover and when i did i found a oil/water sludge on the cap and the mesh breather.

the oil still checks perfect level and nothing but black oil on it when i checked it before cranking it today and right after getting it shut off. and the radiator is still full and clean.

the antifreeze had to went somewhere the first time but not sure where, it looks like clear water dripping off the breather mesh

cat 941 with a engine from a 951b d330c if i remember correctly.

anyone have any ideas what my trouble maybe and where to start looking?

When was the last time the breather cap was removed/cleaned? Overtime atmosphere moisture can have a tendency to build up, and I found (at least on my stuff that is not run consistently and often not for long periods of time) that it tends to collect in the breather cap or on the underside of the oil fill cap. If you had oil getting into your coolant, usually you can see a film when you pop the radiator cap since the oil will separate and float all the way to the top. If it were mine, I’d probably clean everything, put it back together run it and just watch my fluids. You could also send an oil sample off that would tell you if you’re getting coolant in your oil.

But my guess is you just had atmospheric moisture collecting there, especially since you said it was clear.

Hope this helps, I’m sure there are others that have better ideas than me.

Run-away is your first concern - check all linkages, make sure nothing has come loose. Good thinking, often when that happens people forget to cut off the air supply. -- cts

Both @Z1939 and CTS make logical comments. I agree with CTS that finding the cause of the run away would be top of the list. A slow leak somewhere can drop three gallons over 8 months without being noticed (It's why I have a new radiator in the D2). Put some cardboard under the radiator/water pump and see if you get any drips. The breather element seems to be consistent with not being cleaned for a long time and moisture that occurs naturally. You can crack the oil plug and see if water drips out first, if so, you would want to go further.

ill make a new post about the runaway